Trimming machine



Dec. 22, 1959 J. B. BENYAK TRIMMING MACHINE 3 Sheets-Sheet 1 Filed April20, 1955 INVENTOR. JOHN B. fif/VYA/f BY 04% vim/u ATTORNEYS.

J. B. BENYAK TRIMMING MACHINE Dec. 22, 1959 3 Sheets-Sheet 2 Filed April20, 1955 INVENTOR. JUHN 5. BENYAK J. B. BENYAK TRIMMING MACHINE FiledApril 20, 1955 .Illlll l I I L INVENTOR. JOHN B. Bf/VYAK ATTOIE vsxs.

United States Patent Ofiice 2,918,327 Patented Dec. 22, 1959 TRIMMINGMACHINE John B. Benyak, Cleveland, Ohio, assignor to The bornManufacturing Company, Cleveland, Ohio, a corporation of OhioApplication April 20, 1955, Serial No. 502,668

5 Claims. (Cl. 30017) This invention relates as indicated to a trimmingmachine, and more particularly to a machine especially designed for thetrimming of the brush fill material of rotary brushes including brusheshaving exceptionally hard wire brush material.

Power driven rotary brushes ordinarily comprise an annular sheet metalback with brush bristle material extending radially therefrom. Suchbrushes may be composed of a number of axially aligned annular sections,or a length of brush strip may be wound in a helix to form a generallysimilar cylindrical brush. These brushes are widely used in industry andare being driven at faster and faster speeds. For this reason, it isimportant that the brush be properly balanced. For various types ofsurface-finishing operations and when used as back-up wheels, it is alsohighly important that the brush be smoothly and accurately trimmed.

In the past, it has been customary to trim brushes of this type byrotating the brush on an arbor. with its periphery in engagement with atrimmer comprising a rotor carrying a number of long lead helical bladesopposed to a cutter bar, much like the ordinary lawn mower. Machines ofthis type were not adapted to the employment of very hard tool steelssuch as Carbaloy. They wore rapidly and also generated considerableheat. The problem has recently been accentuated by the fact that veryhard wire is now being employed as brush bristle material. The problemis not so acute with organic brush bristle materials such as horsehair,tampico fiber, and synthetic plastic.

For certain types of brushing operations, it will also be desirablesubsequently to grind the brush face to a very precise and uniformcondition.

It is accordingly a principal object of my invention to provide a brushtrimming machine which will operate with a cropping or nibbling actionand which is suitable for the employment of very hard cutting elements.

Another object is to provide such device which will be adapted to trimrotary brushes of the usual cylindrical shape with the axes of suchbrushes disposed either parallel to the cutting edges or normal thereto.

A further object is to provide a trimming machine capable of trimming alarge rotary brush with unusual rapidity but relatively low powerconsumption.

Still another object is to provide a brush trimming machine adapted totrim the brush face in a very uniform and precise manner and yet alsoaccommodate and trim any bristles which may inadvertently protrude anespecially long distance from the brush face.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawing setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however,

of but a few of the various ways in which the principle of the inventionmay be employed.

In said annexed drawing:

Fig. 1 is an end view of my new brushing machine illustrating the mannerin which rotary brushes may be trimmed thereby;

Fig. 2 is a front elevational view of such machine; and

Fig. 3 is a top plan view of the machine.

Referring now more particularly to said drawing, the embodiment of myinvention illustrated therein comprises an outer housing or supporthaving a base plate 1 and a vertical back plate 2 welded thereto andbraced by means of angle braces 3 and 4. Upstanding brackets 5 and 6 arewelded to the respective sides of base plate 1.

Fitting within this outer housing or support is an inner housing ofgeneral box-like form comprising a back plate 7, two side plates 8 and9, a low front plate 10, and a massive top plate 11. A verticallyextending key 12 is secured to back plate 7 and fitted for verticalreciprocation in a way formed by two gibs 13 and 14 bolted to back plate2 of the outer housing. A vertical screw 15 is mounted for free rotationin bracket 16 secured to the upstanding upper edge of rear plate 2. Thisscrew is threadedly engaged in upper deck 11 so that by rotationthereof, the entire inner housing may be raised or lowered. Bolts 17 and18 passing through upstanding brackets 5 and 6 respectively fit in slotssuch as 19 in side plates 8 and 9 and may be tightened to secure theinner housing in desired vertically adjusted position.

A crankshaft 20 is journalled in bearings 21 and 22 mounted on theunderside of deck 11, the respective end portions of such crankshaftextending through slots in side frame members 8 and 9. A flywheel 23 iskeyed to one end of such shaft and a drive pulley 24 is keyed to theother end thereof, adapted in turn to be driven by belt 25.

A rocker shaft 26 is journalled in upstanding brackets 27, 28 and 29 andcutter beams 30 and 31 are pivotally mounted thereon side by-side.Aluminum connecting rods 32 and 33 are pivotally connected to the rearends of arms 30 and 31 respectively and the spaced eccentric bearings ofcrankshaft 20 whereby beams 30 and 31 may be rocked alternately up anddown, the end of beam 30 rising while the corresponding end of beam 31is falling. Upper blades 34, 35, 36 and 37 are firmly clamped inhorizontal slots in the outer ends of beams 30 and 31, screws 38 and 39being provided to constrict such slots firmly to grip the blades. Theseblades are adapted to cooperate with corresponding opposed blades 40,41, 42 and 43 held in lower adjustable supports 44 and 45 by means ofwedges 46 and 47. Supports 44 and 45 are firmly bolted down in ways 48and 49 but are adapted to be reciprocated slightly along such ways bymeans of screws 50 and 51 passing through such supports and threadedlyengaged in a crossbar or bridge 52 secured to the forward faces ofbrackets 27, 28 and 29.

It is desired that the upper and lower blades should be adjustedrelative to each other so that when beams 30 and 31 are rocked throughrotation of crankshaft 20, the upper blades will pass downwardly from anupper position only slightly spaced from the upper edges of the lowerblades to a lower position which may be, for example, approximately 4 ofan inch below the upper edges of such low blades, and with very closeclearance. Accordingly, adjustable supports 44 and 45 will be bolteddown with the lower blades carried thereby positioned a little furtherout from the arcs described by the upper blades in motion and screws 50and 51 will then be tightened to draw the respective supports inwardlyto the desired adjusted positions. For best results, it has been founddesirable to locate the upper edges of the lower blades about two andone-half degrees below the center "thecut.

line of shaft 26 on which the upper cutter carrying beams are pivoted.It is also generally desirable to grind the edges of the cutter bladesto provide a very slight shearing angle so that bristles intrudedtherebetween will be severed first adjacent one side of the blade withthe cut progressing toward the other side. Flywheel 23 serves toequalize the driving force, and smoothness of operation isfurthera'chieved partly as a result of the fact that the blades carriedby one beam alternate with the blades carried by the other beam in theircutting action and partly due to the aforesaid shearing cut which may beobtained.

The brush B may be mounted on a vertical arbor with its axis located thedesired distance from the shearing edges to afford the proper trim. Thebrush will be rapidly rotated and chankshaft 20 likewise driven atrelatively high speed to afford a quick nibbling action ofthe cutters.Simultaneously, the brush will be slowly traversed axially so that theentire brush face will eventually be acted upon. I have found that whentrimming large cylindrical rotary brushes 72 inches long and filled withwire brush material, I am able to trim the entire working face of thebrush in approximately 1 hour whereas on machines previously employedfrom 24 to 32'hours were required. Moreover, only about one-tenth thehorsepower has been found necessary to operate my new machine comparedto that required to operate trimming machines of less capacity in thepast. The figures given relate to two complete passes of the brush facepast the trimming blades. If the brush B is mounted on a horizontal axisas shown in Fig. 1 (the usual arrangement when trimming a longcylindrical brush), both sets of cutting blades may be utilized withmaximum efficiency.

Beams 30 and 31 may ordinarily be rocked at a rate of from about 3,400to 6,000 oscillations per minute and the brush may desirably be rotatedat a high enough speed (e.g. 5,000 rpm.) to cause the wire bristlematerial to extend directly radially outwardly as it will in use, andmore particularly to cause any individual exceptionally long bristles toprotrude to their full extent beyond the principal brush face. Due tothe slight shearing angle of the cutter blades and the slow traverse ofthe brush, such extra long bristles may be caused to enter between theblades and be cut off although they would have difficulty in entering inthe direction of rotation if the brush were not thus traversed. It isgenerally desirable to rotate the brush at a considerably lower speedwhen giving it its initial trim, ordinarily taking a cut of from aboutone-eighth to one inch, and then rotating the brush at the indicatedfairly high speed when taking the second trim which will ordinarily beextremely small.

It will be seen from the foregoing that Ihave achieved the objects of myinvention, and more particularly have provided a brush trimming machinecapable of using very hard tool steels and accordingly able to trimbrushes having relatively hard wire fill. Such trimmer will producesubstantially square cut ends on the individual wire bristles whichrender the brush equally effective in use regardless of the direction ofrotation of the same. It is, moreover, relatively cool running inoperation and does not tend to overheat and anneal the wire bristle endportions, to scorch tampico fiber, or to soften plastic bristle materialsuch as nylon. The rate of production is much increased over anythingpreviously obtainable and at a very consequential reduction in theamount of power consumed. A very uniform trim is achieved, the machinebeing adapted both to cut off exceptionally long protruding bristle endportions and also to take a very fine cut.

The distance the upper blades .are rocked above the lower bladesdetermines the quantity of brush material which. will be intrudedtherebetween and thereby meters ligiof an inch... When trimminga longcylindrical brush,

Such distance will usually be between 'and' the latter will be rotatedin the direction of the arrow on Fig. 1 (downwardly toward the cuttingblades) with the axis of rotation slightly below the horizontal planeincluding the lower blade edge. When trimming a brush of inch radius,such axis should be about inch below such plane, and when trimming abrush of 10 inch radius such axis should be about inch below such plane.

One or more sets of opposed blades may be utilized, it being appreciatedthat the more sets the more quickly a long cylindrical brush may betrimmed. By rocking the two beams alternately to make a cut, powerrequirements are reduced and the operation of the machine is smoother.When trimming a narrow rotary brush section, however, but one set ofopposed blades may be utilized regardless of whether such section isrotated about a horizontal or vertical axis. The eccentric hearings orcranks to which the connecting rods connect will ordinarily havediametrically opposite throws for the reason explained above. Thebladeswillnormally be bevelled in the general manner indicated in Fig. 1 andmay be quite stubby and solid in contrast to the blades of previouslyknown trimming machines which have a-tendency to destructive vibration.A serious deficiency of rotary trimmers has been their inability to cutoff more than about inch of bristle length at a timewhere as my newtrimming machine will readily handle cuts 8 to 16 times as long. Thereis a consequent saving in time and a great reduction in the amount ofdestructive heat generated. By positioning the cutting edge'ofupstanding blade 43 slightly below the axis of shaft 26, blade 37 iscaused to extend at a slightly obtuse angle to such upstanding blade,the lower'face of blade 37'lying in a plane generally radial of suchaxis and the inner face of blade 43 being substantially vertical. Thecrankshaft may be mounted with its eccentric throws directly engagingthe ends of rocker beams 30 and 31 when especially rapid oscillation ofthe latter is desired. The opposed-blades afford a rapid nibbling actionwhich I have found to achieve a very uniform trim.

In the past, brushes having relatively short wire bristles and heavilyfilled dense faces have usually required to be ground to obtainsufficient uniformity and this has not only involved extra expense'buthas tended to overheat and anneal the wire bristle ends, reducingtheireffectiveness. When employing my new trimming machine, however, theneed for such subsequent grinding op. erations is frequently eliminatedwith consequent saving in costand improvement in the brushing action ofthe finished brush. While particularly useful in the trimming of rotarybrushes, it is obvious that other types including lengths of brush stripand the like may also be handled.

Other modes of applying the principle of the-invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a trimming machine for trimming the brush material of rotarybrushes and the like, a stationary base frame, a housing mounted on saidbase frame for adjustment relative thereto, a crankshaft journalled insaid housing, a drive pulley on one end and a flywheel on the other endof said shaft, a heavy upper deck on said housing, a'pair of cutterblade supports mounted in ways on said deck for adjustment forwardly andrearwardly of said housing, stationary blades carried by said supports,a pair of beams pivotally supported on said deck for rocking movementabout aligned axes parallel tosaid-blades, movable blades carried by theouter ends of said beams positioned to cooperate with said stationaryblades to cut brush material interposed therebetween, said supports forsaid stationary blades being adjusted to bring the latter just outsidethe arcs described by said movable blades when said beams are rocked, apair of cranks on said crankshaft having diametrically opposite throws,and connecting rods connecting said respective beams and crankssimultaneously to rock said beams in opposite directions.

2. In a trimming machine for trimming the brush material of rotarybrushes and the like, a stationary base frame having a vertical backplate, a vertical way on said back plate, an inner box-like housinggibbed for vertical reciprocation along such way, and screw meansoperable thus to reciprocate said housing; said housing comprising aback plate, two side plates, and a heavy horizontal upper deck; ahorizontal crankshaft supported in said housing, a drive pulley on oneend and a flywheel on the other end of said shaft, a pair of parallelways in the upper surface of said deck extending rearwardly from theforward edge thereof, lower blade supports respectively fitted forreciprocation in said ways, clamping means operative to clamp saidsupports frictionally to resist such reciprocation, upstanding bracketson said deck rearwardly of said supports, a pair of beams pivotallymounted in said brackets for rocking movement about aligned axes atright angles to said parallel Ways, a pair of upstanding blades havinggenerally aligned substantially horizontal cutting edges clamped in eachof said supports, a pair of generally horizontal projecting bladeshaving aligned cutting edges clamped in the forward ends of each of saidbeams in position to cooperate with said upstanding blades to cut brushmaterial interposed therebetween, and screw means operable to shift saidsupports along their respective ways to bring the cutting edges of saidupstanding blades just outside the arcs described by the cutting edgesof said blades on said beams as the latter are rocked, the cutting edgesof said upstanding blades being ground to provide slight shearing anglesin the same direction and being located approximately 2 /2 degrees belowthe pivotal axes of said beams; -a pair of cranks on said crankshafthaving diametrically opposite throws, and connecting rods connectingsaid respective beams and cranks simultaneously to rock said beams inopposite directions, said cranks and rods being proportioned thus torock said beams to rock said blades carried thereby in an are from about7 inch above the cutting e lges of the opposed upstanding blades toabout inch therebelow.

3. In a trimming machine for trimming the brush material of rotarybrushes and the like, a frame, a crankshaft journalled for rotationtherein, drive means on one end of said shaft, a flywheel on the otherend of said shaft, a pair of lower blade supports mounted on said framefor side-by-side front-to-rear adjustment thereon, upstanding bladeshaving generally aligned cutting edges secured in said supports, a pairof beams pivotally mounted on said frame for rocking movement aboutaligned axes extending transversely of said frame, blades having alignedcutting edges carried by said beams in position to cooperate with saidupstanding blades to cut brush material interposed therebetween, saidlower blade supports being adjusted to bring the cutting edges of saidupstanding blades just outside the arcs described by the cutting edgesof said blades on said beams as the latter are rocked, the cutting edgesof said upstanding blades being ground to provide slight shearing anglesin the same direction, a pair of cranks on said crankshaft havingdiametrically opposite throws, and connecting rods connecting saidrespective beams and cranks simultaneously to rock said beams inopposite directions rapidly to oscillate said blades on said beams pastthe cutting edges of said corresponding upstanding blades.

4. In a trimming machine for trimming the brush material of rotarybrushes and thelike, a frame, a pair of lower blade supports mounted onsaid frame for sideby-side front-to-rear adjustment thereon. upstandingblades having generally aligned cutting edges secured in said supports,a pair of beams pivotally mounted on said frame for rocking movementabout aligned axes extending transversely of said frame, blades havingaligned cutting edges carried by said beams in position to cooperatewith said upstanding blades to cut brush material interposedtherebetween, said lower blade supports being adjusted to bring thecutting edges of said upstanding blades just outside the arcs: describedby the cutting edges of said blades on said beams as the latter arerocked, and drive means operative simultaneously to rock said beams inopposite directions rapidly to oscillate said blades on said beams pastthe cutting edges of said corresponding upstanding blades.

5. In a trimming machine for trimming the brush material of rotarybrushes and the like, a frame, a crankshaft journalled for rotationtherein, drive means on one end of said shaft, a flywheel on the otherend of said shaft, a lower blade support mounted on said frame forfront-to-rear adjustment thereon, an upstanding blade secured in saidsupport, a beam pivotally mounted on said frame for rocking movementabout an axis extending transversely of said frame, a blade carried bysaid beam in position to cooperate with said upstanding blade to cutbrush material interposed therebetween, said lower blade support beingadjusted to bring the cutting edge of said upstanding blade just outsidethe are described by the cutting edge of said blade on said beam as thelatter is rocked, the cutting edge of said upstanding blade being groundto provide a slight shearing angle, a crank on said crankshaft,and aconnecting rod connecting said crank and beam to rock the latter rapidlyto oscillate said blade carried thereby past the cutting edge of saidupstanding blade.

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